16.8: Digital Conservation and Restoration

For centuries, replicas or surrogates have been made of important objects, e.g. casts of famous sculptures. The aim was to provide access to people who could not see the ‘real’ thing. Figure 5 shows a silver decadrachm of Syracuse (5^th century BC) in the British Museum (Figure 5a) together with two forms of 19^th-century surrogate — a silver electrotype (Figure 5b) and a moulded paper ‘squeeze’ (Figure 5c). For the same reasons, copies of texts have been made either as transcripts or in print. The advent of photography meant that the appearance of the text could be captured, so original texts could be conserved by limiting access and providing a photographic copy. Today, digital imaging has enormously expanded the possibilities of viewing and studying damaged and fragmentary text (MacDonald 2006).

This expanded use of digital imaging and of surrogates, has led to the use of the phrase ‘digital preservation’ or ‘informational preservation’ (Keene 2005: 138; Muñoz Viñas 2005: 23). It has changed the balance of risk and benefit since the original material is exposed to fewer risks (perhaps only the one-off manipulation needed to make a clear image) and the text becomes readily accessible. This form of conservation is now in common use for newspapers (which, being printed on low-grade paper, deteriorate very readily; British Library 2009a). Today’s newspaper is replaced with tomorrow’s surrogate, and only selected examples of the original newspaper are kept for evidence and legal reasons (put into permanent, controlled and, effectively, inaccessible storage).

Perhaps the most remarkable example of a major document now digitally imaged, virtually reunited, and accessible on a dedicated website is the Codex Sinaiticus. This is the earliest surviving copy of the Christian Bible and one of the earliest known bound books, different parts of which are held in different institutions (in Egypt, Germany, Russia, and the UK). On the website there is information about the conservation needed to prepare for imaging, and it is possible to view the pages in both normal and raking light, displaying a realistic impression of their condition (raking light throws surface topography into visible relief thus giving an indication of the materiality of both text and substrate; Codex 2009).

Furthermore, digital imaging, particularly 3D imaging, has introduced the possibilities of digital investigation and digital restoration. Details of text can be digitally enhanced and the image, or the 3D virtual model, can be moved or rotated to achieve a better view — all without manipulation or damage to the material original. This is particularly useful with cuneiform tablets as they are cushion-shaped with the text often running over the edge and onto the rounded sides making it impossible to view all the text in the same plane (Hahn et al. 2006; Kumar et al. 2003). Whereas hitherto the only way to enhance text was to modify the original object (e.g. white paint applied to the lettering on the Rosetta Stone as recently as 1981, see British Museum 2009), digital imaging can be used to enhance lettering without touching the original. This has been used on fragmentary papyri, and has the potential to aid matching up and repositioning separated fragments (Sparavigna 2009). Reflectance Transformation Imaging (RTI) is also being used to flesh out the faint inscriptions (Earl et al. 2011) and details of ductus, and tool and technique types used by past scribes (Piquette forthcoming). Furthermore, Stephen Quirke (2011) discusses the potential of using digital images for computer aided palaeography. Digital enhancement can also be used both to ‘clean’ stained or foxed paper and to increase definition of the written text without intervention on the material original, thus avoiding the use of washing or bleaching processes which may have limited visual success and be potentially damaging (Ramponi et al. 2005).